The interview process is pretty relaxed and enjoyable. Usually, you'll be presented with a online test followed by a phone screening interview. This interview should be a blend of questions on your resume, few knowledge based questions and coding questions. The interviewer would be more interested in your problem solving approach so try to vocalize the approach before starting to code. If, this goes fine. they'll fly you to Redwood City for a on-site almost a day-long interview. I had series of 5 interviewers interviewing me each with different domain of questions.
Expect questions on basic data structures, algorithms, design questions and that should be all mostly.